CN104291813B - A kind of preparation surveying hydrogen solid electrolyte tube and manufacturing process - Google Patents

Abstract

The invention discloses a preparation and forming method of a solid electrolyte tube for measuring hydrogen. The method uses CaCO ₃ , ZrO ₂ , and In ₂ O ₃ raw materials, according to the molar ratio: CaCO ₃ : ZrO ₂ : In ₂ O ₃ = 1: 0.8-0.95: 0.025-0.1 Weigh out the raw materials, carry out wet grinding and mixing, and mix The powder is pressed into a disc with a diameter of 20-30mm and a thickness of 2-5mm, and calcined at 1000-1400°C to obtain CaZr _1-x In _x O _3-α (0.05≤x≤0.2, atomic ratio), and then the disc Crushed into powder, added to the molten paraffin, oleic acid and beeswax mixture, stirred with an electromagnetic stirrer, formed into a tube by hot pressing method, and then dewaxed at high temperature, and then carried out at 1450-1550 ° C After final sintering, a CaZr _1-x In _x O _3-α (0.05≤x≤0.2) electrolyte tube is obtained. The electrolyte tube has a smooth surface and a compact structure, has good chemical stability and thermal shock resistance, and can be applied to the continuous and accurate determination of the hydrogen content of aluminum and magnesium alloy melts under variable temperature environments.

Description

Preparation and forming method of a solid electrolyte tube for hydrogen measurement

technical field

The invention belongs to the field of metallurgical quality detection, and relates to a hydrogen-measuring sensor technology for aluminum and magnesium alloy melts, in particular to a method for preparing and forming a solid electrolyte tube.

Background technique

During the smelting process of aluminum alloy and magnesium alloy, the melt easily reacts with the furnace gas and the moisture in the furnace refractory material to absorb hydrogen. When the aluminum and magnesium alloy melt solidifies, a large amount of hydrogen is precipitated in the form of molecules, causing defects such as pinholes and micro-shrinkage in the casting. With the increasing amount and application range of aluminum and magnesium alloys, people pay more and more attention to the measurement method of hydrogen content in alloy melts, hoping to realize accurate determination of hydrogen content in aluminum and magnesium alloy melts to guide production. At present, the hydrogen measurement methods (such as the first bubble method, Telegas method, etc.) that are widely used in production have the disadvantages of long detection time and inability to realize online continuous measurement. As a new hydrogen measurement method, the concentration cell method greatly overcomes these shortcomings. This hydrogen measurement method can almost instantaneously measure the hydrogen content of the melt, so it can realize online, continuous and precise measurement.

The concentration cell method is to use a solid electrolyte to form a concentration cell between the aluminum liquid to be measured and a substance with a constant hydrogen partial pressure, measure the electromotive force and temperature of the battery, and obtain the hydrogen content in the aluminum liquid by the Nernst (Nernst) equation. quantity. The solid electrolyte is a key part of the concentration difference battery method, and its conductivity and ion migration number have an important impact on the quality of the concentration difference battery. At present, solid electrolytes have three structures: sheet, cylinder, and tube. Among them, the solid electrolyte with tubular structure is a relatively mature one at present, and its performance is excellent and stable.

At present, the domestic inventions in the concentration cell method for measuring hydrogen sensors mainly include, the Chinese patent document "A Hydrogen Sensor Reference Electrode and Its Preparation Method" (publication number CN1097508A) invented a kind of hydrogen sensor using yttrium-hydrogen alloy as the hydrogen sensor. Solid electrolyte for the sensing reference electrode. Compared with the Japanese sensor using 1% hydrogen standard gas as the reference electrode, the sensor is more convenient to carry and replace, and the cost is lower. The Chinese patent "A Method and Device for Measuring Hydrogen Pressure in Solid Steel" (Notice No. CN101661016A) invented a method using BaCe _0.85～0.9 Y _0.1～0.15 O _3-ɑ or Ba ₃ Ca _1.18 Nb _1.82 O _9-δ or ZrO2 _{doped Y2O3} as a solid electrolyte, using ₁ % standard hydrogen as a sensor for the reference electrode. Compared with the traditional method of taking steel samples for vacuum melting and measuring hydrogen, the sensor has the characteristics of low price and easy use. The Chinese patent "A Preparation Method for Hydrogen Measuring Sensor and Solid Electrolyte" (Notice No. CN101071119A) invented a kind of measuring method using BaCeO ₃ doped Y ₂ O ₃ as solid electrolyte and yttrium-hydrogen alloy as reference electrode. hydrogen sensor. The sensor has the characteristics of high precision, low cost, easy to carry and easy to operate.

In recent years, the research on concentration cell hydrogen sensors has made great progress, but there are few applications in industrial environments. In terms of concentration battery hydrogen sensors, the development of SrCeO ₃ -based and BaCeO ₃ -based proton conductors and CaZrO ₃ -based and BaZrO ₃ -based proton conductors has been developed as solid electrolyte hydrogen sensors, although the SrCeO ₃ -based and BaCeO ₃ -based proton conductors Compared with _CaZrO3 -based and BaZrO3 _- based proton conductors, conductors have higher electrical conductivity, but their chemical stability and mechanical strength are lower, so the actual production of hydrogen sensors using _CaZrO3 -based and BaZrO3 _- based proton conductors as solid electrolytes is better. it is good. The CaZrO ₃ -based and BaZrO ₃ -based electrolyte tubes currently used in experiments cannot achieve continuous measurement in a variable temperature environment, and many of them have not been commercialized. It is urgent to optimize the preparation method of solid electrolyte tube materials, and to combine electrolyte materials Formed into parts for the manufacture of sensors for the measurement of the hydrogen content of melts at varying temperatures.

Contents of the invention

The object of the present invention is to aim at the above-mentioned present situation, and aims to provide a preparation method and a forming method of a solid electrolyte tube that is easy to synthesize and easy to shape.

In order to achieve the above object, the present invention includes two parts: preparation of solid electrolyte material and forming of solid electrolyte tube;

The preparation method of the solid electrolyte material comprises the following steps:

(1.1) Mixture:

The molar ratio of CaCO ₃ , ZrO ₂ and In ₂ O ₃ is: CaCO ₃ : ZrO ₂ : In ₂ O ₃ = 1: 0.8~0.95: 0.025~0.1 for wet ball milling at a speed of 200~300r/min Alternate forward and reverse ball milling for 8 to 24 hours, dry after ball milling, and then sieve the dried powder to obtain a mixed powder with a particle size of less than 5 μm;

(1.2) Solid phase synthesis:

Pour the sifted mixed powder into a mold to make a disc, put the pressed tablet into a high-temperature calcination furnace, perform high-temperature solid-phase reaction synthesis under normal pressure and air atmosphere, and then cool to room temperature with the furnace ;

(1.3) Pulverization:

The solid electrolyte sheet synthesized by the high-temperature solid-state reaction is crushed, then wet ball milled, then dried and sieved to obtain an electrolyte powder with a particle size of less than 5 μm;

The forming of the solid electrolyte tube includes the following steps:

(2.1) Forming slurry preparation:

preparing the electrolyte powder material together with a flowable substance that can be removed by subsequent heating to form a slurry;

(2.2) Hot pressing injection molding:

Pour the slurry into the slurry cylinder of the hot press injection molding machine, control the temperature of the wax slurry to 70-90°C through the heating oil bath, and fill the heat transfer liquid medium between the slurry cylinder and the heating oil bath to facilitate heat transfer and uniform temperature , control the temperature of the grouting port at 40-50°C; then place the mold at the riser nozzle of the hot-press injection molding machine, use the cylinder to compress the mold, control the cylinder pressure to 0.3-0.5MPa, and press the slurry cylinder to Inject the slurry into the mold, hold the pressure for 5-15 seconds, take out the mold, demold the mold, and obtain the electrolyte tube;

(2.3) Waxing discharge:

Heat the formed electrolyte tube under normal pressure and air atmosphere to remove wax. The temperature rise system for wax removal is as follows: from room temperature to 100-150°C, with a heating rate of 0.1-0.3°C/min; at 100-150°C, keep warm for 3-7 hours; 100～150℃ to 400～600℃, the heating rate is 0.2～0.5℃/min; 400～600℃ for 1～3h; 400～600℃ to 950～1050℃, the heating rate is 0.5～2℃/min; 950 ～1050℃ for 1～3h; cool down to room temperature with the furnace;

(2.4) Sintering:

Sinter the electrolyte tube after dewaxing at high temperature under normal pressure and air atmosphere. ℃ to 1450-1550 ℃, the heating rate is 1.5-2.5 ℃/min; 1450-1550 ℃ heat preservation 5-15h; cool to room temperature with the furnace, and finally obtain a solid electrolyte tube.

The present invention has the following characteristics:

(1) The perovskite-type proton conductor solid electrolyte can be obtained by using a high-temperature solid-state reaction method, which is simple and has a high success rate of material preparation. Figure 1 shows the X-ray diffraction pattern of the high-temperature synthetic material. High-purity CaZr _1-x In _x O _3-α (0.05≤x≤0.2, atomic ratio) was obtained, and the reaction success rate was close to 100%.

(2) The present invention adopts the In-doped _CaZrO3 matrix as the proton conductor, and the material is basically a pure proton conductor in the operating temperature range (700-850° C.), and its chemical stability and thermal shock resistance are relatively good, so it can be used to manufacture electric Chemical hydrogen sensor element.

(3) Electromagnetic stirring (or mechanical stirring, or vacuum electromagnetic stirring, or vacuum mechanical stirring) is used during the preparation of the forming slurry to obtain a slurry with a high CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder ratio Material, the subsequent wax removal time of the formed electrolyte tube blank is short and easy to remove.

(4) The CaZr _1-x In _x O _3-α (0.05≤x≤0.2) solid electrolyte tube obtained by hot pressing injection molding has a compact structure and a smooth tube wall. Figure 2 shows the CaZr _1-x In _x O _3-α (0.05≤x≤0.2) solid electrolyte tube formed and sintered by this method. It is a ceramic tube with one end open and one end closed (as shown in Figure 2), the outer diameter of the tube is 5-10 mm, the inner diameter is 3-8 mm, and the tube length is 15-30 mm.

(5) The CaZr _1-x In _x O _3-α (0.05≤x≤0.2) solid electrolyte tube prepared by the present invention has high density, strong chemical stability and thermal shock resistance, and has certain mechanical properties, which can meet the requirements of Continuous measurement of hydrogen content in high temperature melts in a variable temperature environment.

Description of drawings

Figure 1 is the XRD pattern of CaZr _1-x In _x O _3-α (0.05≤x≤0.2) synthesized by solid state reaction at 1400°C;

Fig. 2 is the formed CaZr _1-x In _x O _3-α (0.05≤x≤0.2) solid electrolyte tube of the present invention;

Fig. 3 is a schematic diagram of hot press injection molding;

In the figure: 1—heating wire; 2—liter pipe; 3—slurry; 4—cylinder; 5—mold; 6—slurry cylinder; 7—heating oil bath; 8—water.

detailed description

The present invention firstly prepares the solid electrolyte material for hydrogen measurement—In-doped CaZrO ₃ , that is, CaZr _1-x In _x O _3-α (0.05≤x≤0.2) through a high-temperature solid-state reaction method, which involves the selection of raw materials and proportioning, as well as the solid phase reaction calcination process; then use the hot press injection molding method to form a solid electrolyte tube, which involves the control principles of slurry preparation, forming temperature, forming pressure and other forming process parameters; finally the formed tube Wax removal from the body and sintering the CaZr _1-x In _x O _3-α (0.05≤x≤0.2) solid electrolyte tube, which involves wax removal temperature rise system and sintering temperature rise system.

The method of the present invention comprises two parts, the preparation of the solid electrolyte material and the forming of the solid electrolyte tube, specifically described as follows:

1. Preparation method of solid electrolyte material

The raw materials are CaCO ₃ , ZrO ₂ , In ₂ O ₃ powders, and the ratio of raw materials is:

According to the molar ratio: CaCO ₃ : ZrO ₂ : In ₂ O ₃ =1: 0.8～0.95: 0.025～0.1

The material preparation process steps are as follows.

(1.1) Mixing

Put CaCO ₃ , ZrO ₂ and In ₂ O ₃ into the ball mill tank according to the ratio of raw materials, add appropriate amount of absolute ethanol or acetone, and wet ball mill in the ball mill, and alternate ball milling in forward and reverse directions at a speed of 200-300r/min , the intermittent time of each ball mill is 10-30 minutes and the cumulative ball mill is 8-24 hours. After the ball milling, the powder is dried and sieved to obtain a mixed powder with a particle size of less than 5 μm.

(1.2) High temperature solid phase synthesis

The sieved mixed powder is pressed into a tablet with a hydraulic press in a mold, and the pressed tablet is calcined under normal pressure and air atmosphere. Calcination heating system: from room temperature to 700-900°C, the heating rate is 5-10°C/min; Keep warm at 1000～1400℃ for 5～15 hours; cool down to room temperature with the furnace.

The diameter of the mixed powder disk can be 20-30 mm, and the thickness can be 2-5 mm.

(1.3) Grinding and refining

The CaZr _1-x In _x O _3-α (0.05≤x≤0.2) flakes prepared by high-temperature solid-state reaction are crushed and then put into a ball mill and added with appropriate amount of absolute ethanol or acetone for wet ball milling. Ball milling procedure: Alternate forward and reverse ball milling at a speed of 200-300r/min, the interval time of each ball milling is 10-30 minutes, and the cumulative ball milling time is 8-24 hours. After drying and sieving, CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder with a particle size of 1-5 μm is obtained.

2. Forming method of solid electrolyte tube

(2.1) Forming slurry preparation

In order to facilitate hot-press injection molding of the electrolyte powder into the electrolyte tube, the above-mentioned electrolyte powder material and a flowable substance (which should be removable after subsequent heating) are prepared into a slurry. Flowable substances are selected from paraffin, beeswax and oleic acid.

The concrete mass ratio of powder, paraffin, beeswax and oleic acid is as follows:

Powder: Paraffin: Beeswax: Oleic Acid

80-95%: 16-4%: 3.0-0.5%: 1.0-0.1%

Heat paraffin and beeswax in a constant temperature water bath (or constant temperature oil bath) at 70-90°C until completely melted, then add oleic acid and stir with a glass rod, after the paraffin, beeswax and oleic acid are mixed evenly, add CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder, stir CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder evenly, then continue to stir to remove the gas in the slurry and adjust the viscosity of the slurry consistency.

As a preferred method, a certain amount of paraffin wax and beeswax can be weighed and put into a flask, heated in a constant temperature water bath (or constant temperature oil bath) at 70-90°C until completely melted, then a certain amount of oleic acid is added and stirred with a glass rod, and the After the oleic acid is mixed evenly, add CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder several times, so that the CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder is stirred evenly, After the powder is added, add a small amount of oleic acid, paraffin and beeswax to improve the viscosity of the slurry, and then stir for 2-7 days to fully degas and make the slurry fully uniform.

(2.2) Hot pressing injection molding

Use a hot-press injection molding machine for hot-press injection molding, control the temperature of the slurry at 70-90°C, the temperature of the grouting port at 40-50°C, the molding pressure at 0.3-0.5MPa, and the holding time for 10-20s. The obtained solid electrolyte tube green body has an outer diameter of 7-10 mm, an inner diameter of 3-6 mm, and a length of 15-30 mm.

(2.3) Wax removal

Heat the formed pipe body under normal pressure and air atmosphere to remove wax. Wax removal heating system: from room temperature to 100-150°C, the heating rate is 0.1-0.3°C/min; at 100-150°C, keep warm for 3-7h; from 100-150°C to 400-600°C, the heating rate is 0.2-0.5°C/min min; heat preservation at 400-600°C for 1-3 hours; 400-600°C to 950-1050°C with a heating rate of 0.5-2°C/min; heat preservation at 950-1050°C for 1-3 hours; cool down to room temperature with the furnace.

(2.4) Sintering

The pipe body after wax removal is sintered at high temperature under normal pressure and air atmosphere. Sintering heating system: from room temperature to 900-1100°C, the heating rate is 3-5°C/min; at 900-1100°C for 1-2 hours; from 900-1100°C to 1450-1550°C, the heating rate is 1.5-2.5°C/min; Insulate at 1450-1550°C for 5-15 hours; cool down to room temperature with the furnace to obtain a CaZr _1-x In _x O _3-α (0.05≤x≤0.2) ceramic solid electrolyte tube.

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted here that the descriptions of these embodiments are used to help understand the present invention, but are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

Example 1

Figure 1 shows that the synthesis process of CaZr _1-x In _x O _3-α (0.05≤x≤0.2) material obtained by X-ray diffraction detection is as follows.

The raw materials are CaCO ₃ , ZrO ₂ , In ₂ O ₃ , and the ingredients are prepared according to the following molar ratio:

CaCO ₃ : ZrO ₂ : In ₂ O ₃ = 1: 0.9: 0.05

Put CaCO ₃ , ZrO ₂ and In ₂ O ₃ into the ball milling tank according to the above proportions, add an appropriate amount of absolute ethanol as the ball milling medium, and perform wet ball milling in the ball mill, with forward and reverse intermittent ball milling at a speed of 250r/min , The intermittent time of each ball mill is 25 minutes and the cumulative ball mill is 16 hours. The powder after ball milling is dried and sieved. The sieved mixed powder is made into a disc with a diameter of 25 mm and a thickness of 3 mm by a hydraulic machine, and the disc is put into a high-temperature calciner and calcined under normal pressure and air atmosphere. Calcination heating system: from room temperature to 800°C, the heating rate is 5°C/min; 800°C for 2 hours; 800°C to 1400°C, the heating rate is 3°C/min; 1400°C for 10 hours; cool down to room temperature with the furnace. Figure 1 shows the XRD pattern of the high-temperature synthetic material, indicating that high-purity CaZr _1-x In _x O _3-α (0.05≤x≤0.2) was obtained.

The CaZr _1-x In _x O _3-α (0.05≤x≤0.2) flakes prepared by the high-temperature solid-state reaction are crushed and then put into a ball mill and added with an appropriate amount of absolute ethanol for wet ball milling. Ball milling procedure: Alternate ball milling at a speed of 250r/min, forward and reverse intermittently, the interval time of each ball milling is 20 minutes, and the cumulative ball milling time is 16 hours. After drying and sieving, a CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder with a particle size of less than 5 μm is obtained.

The resulting CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder is prepared according to the following ratios of powder, paraffin, beeswax and oleic acid for hot press injection molding:

Powder: Paraffin: Beeswax: Oleic Acid

85%: 12%: 2.9%: 0.1%

The specific process is: weigh a certain amount of paraffin and beeswax, put them into a flask, heat them in a water bath with a constant temperature of 80°C until they are completely melted, then add a certain amount of oleic acid and stir with a glass rod, after the oleic acid is evenly mixed, add CaZr _{1 -x} In _x O _3-α (0.05≤x≤0.2) powder, after the powder is added, add the remaining oleic acid, paraffin and beeswax to improve the viscosity of the slurry, and then stir it with electromagnetic stirring for 7 days. Degassing and homogenizing the slurry well.

Put the stirred slurry into the hot press injection molding machine, as shown in Figure 3, pour the stirred slurry 3 into the slurry cylinder 6 of the hot press injection molding machine, and control the wax slurry by heating the oil bath 7 The temperature is 70°C, and water 8 is filled between the slurry cylinder 6 and the heating oil bath 7 to facilitate heat transfer and uniform temperature, and the temperature of the grouting port is controlled by the heating wire 1 to be 45°C. After that, the mold 5 is placed at the mouth of the riser pipe 2 of the hot-press injection molding machine, and the mold 5 is pressed by the cylinder 4, and the pressure of the cylinder is controlled to be 0.4MPa, and the slurry 3 in the slurry cylinder is injected into the In the mold 5, the mold 5 was taken out after holding the pressure for 15 seconds, and demolded to obtain a solid electrolyte tube blank with one end open and one end closed. The outer diameter of the tube was 8 mm, the inner diameter was 5 mm, and the length was 20 mm.

Heat the formed pipe body under normal pressure and air atmosphere to remove wax. Wax removal heating system: from room temperature to 120°C, the heating rate is 0.2°C/min; at 120°C, hold for 5 hours; from 120°C to 500°C, the heating rate is 0.3°C/min; at 500°C for 2 hours; The rate is 1°C/min; hold at 1000°C for 2h; cool down to room temperature with the furnace.

The pipe body after dewaxing is put into a high-temperature sintering furnace, and sintered at high temperature under normal pressure and air atmosphere. The sintering heating system is as follows: from room temperature to 1000°C, the heating rate is 4°C/min; at 1000°C for 1.5h; from 1000°C to 1500°C, the heating rate is 2°C/min; at 1500°C for 10h; naturally cool to room temperature with the furnace. Finally, a CaZr _1-x In _x O _3-α (0.05≤x≤0.2) ceramic solid electrolyte tube is obtained.

Example 2

The raw materials are CaCO ₃ , ZrO ₂ , In ₂ O ₃ , and the ingredients are prepared according to the following molar ratio:

CaCO ₃ : ZrO ₂ : In ₂ O ₃ = 1: 0.8: 0.1

Put CaCO ₃ , ZrO ₂ and In ₂ O ₃ into the ball milling tank according to the above proportions, add an appropriate amount of absolute ethanol as the ball milling medium, and perform wet ball milling in the ball mill, with forward and reverse intermittent ball milling at a speed of 200r/min , each interval of ball milling is 10 minutes and the cumulative ball milling is 8 hours. The powder after ball milling is dried and sieved. The sieved mixed powder is made into a disc with a diameter of 30 mm and a thickness of 2 mm by a hydraulic machine, and the disc is put into a high-temperature calciner and calcined under normal pressure and air atmosphere. Calcination heating system: from room temperature to 700°C, the heating rate is 10°C/min; 700°C for 0.5h; 700°C to 1000°C, the heating rate is 1.5°C/min; 1000°C for 15h; cool to room temperature with the furnace.

The CaZr _1-x In _x O _3-α (0.05≤x≤0.2) flakes prepared by the high-temperature solid-state reaction are crushed and then put into a ball mill and added with an appropriate amount of absolute ethanol for wet ball milling. Ball milling procedure: Alternate forward and reverse ball milling at a speed of 200r/min, the interval time of each ball milling is 10 minutes, and the cumulative ball milling time is 8 hours. After drying and sieving, a CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder with a particle size of less than 5 μm is obtained.

The resulting CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder is prepared according to the following ratios of powder, paraffin, beeswax and oleic acid for hot press injection molding:

Powder: Paraffin: Beeswax: Oleic Acid

80%: 16%: 3%: 1%

The specific process is: weigh a certain amount of paraffin and beeswax, put them into a flask, heat them in a water bath at a constant temperature of 70°C until they are completely melted, then add a certain amount of oleic acid and stir with a glass rod, after the oleic acid is evenly mixed, add CaZr _{1 -x} In _x O _3-α (0.05≤x≤0.2) powder, after the powder is added, add the remaining oleic acid, paraffin and beeswax to improve the viscosity of the slurry, and then use vacuum electromagnetic stirring for 2 days to degas and fully homogenize the slurry.

Put the stirred slurry into the hot press injection molding machine, as shown in Figure 3, pour the stirred slurry 3 into the slurry cylinder 6 of the hot press injection molding machine, and control the wax slurry by heating the oil bath 7 The temperature is 70°C, and water 8 is filled between the slurry cylinder 6 and the heating oil bath 7 to facilitate heat transfer and uniform temperature, and the temperature of the grouting port is controlled by the heating wire 1 to be 40°C. After that, the mold 5 is placed at the mouth of the riser pipe 2 of the hot-press injection molding machine, and the mold 5 is pressed by the cylinder 4, and the pressure of the cylinder is controlled to 0.5MPa, and the slurry 3 in the slurry cylinder is injected into the In the mold 5, the mold 5 was taken out after holding the pressure for 10 seconds, and demolded to obtain a solid electrolyte tube blank with one end open and one end closed. The outer diameter of the tube was 5 mm, the inner diameter was 3 mm, and the length was 15 mm.

Heat the formed pipe body under normal pressure and air atmosphere to remove wax. Wax removal heating system: from room temperature to 100°C, the heating rate is 0.1°C/min; at 100°C, hold for 3 hours; from 100°C to 400°C, the heating rate is 0.2°C/min; at 400°C for 1 hour; from 400°C to 950°C, heat The rate is 0.5°C/min; hold at 950°C for 1 hour; cool down to room temperature with the furnace.

The pipe body after dewaxing is put into a high-temperature sintering furnace, and sintered at high temperature under normal pressure and air atmosphere. The sintering heating system is as follows: from room temperature to 900°C, the heating rate is 5°C/min; at 900°C for 2 hours; from 900°C to 1450°C, the heating rate is 1.5°C/min; at 1450°C for 15 hours; naturally cool to room temperature with the furnace. Finally, a CaZr _1-x In _x O _3-α (0.05≤x≤0.2) ceramic solid electrolyte tube is obtained.

Example 3

The raw materials are CaCO ₃ , ZrO ₂ , In ₂ O ₃ , and the ingredients are prepared according to the following molar ratio:

CaCO ₃ : ZrO ₂ : In ₂ O ₃ = 1: 0.95: 0.025

Put CaCO ₃ , ZrO ₂ and In ₂ O ₃ into the ball milling tank according to the above ratio, add an appropriate amount of acetone as the ball milling medium, and carry out wet ball milling in the ball mill, with the speed of 300r/min. The intermittent time of ball milling is 30 minutes and the cumulative ball milling time is 24 hours. The powder after ball milling is dried and sieved. The sieved mixed powder is made into a disc with a diameter of 20 mm and a thickness of 5 mm by a hydraulic machine, and the disc is put into a high-temperature calciner and calcined under normal pressure and air atmosphere. Calcination heating system: from room temperature to 900°C, the heating rate is 5°C/min; 900°C for 2 hours; 900°C to 1400°C, the heating rate is 5°C/min; 1400°C for 5h;

The CaZr _1-x In _x O _3-α (0.05≤x≤0.2) flakes prepared by the high-temperature solid-state reaction are crushed and then put into a ball mill and added with an appropriate amount of acetone for wet ball milling. Ball milling procedure: Alternate ball milling at a speed of 300r/min, forward and reverse intermittently, the interval time of each ball milling is 30 minutes, and the cumulative ball milling time is 24 hours. After drying and sieving, a CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder with a particle size of less than 5 μm is obtained.

The resulting CaZr _1-x In _x O _3-α (0.05≤x≤0.2) powder is prepared according to the following ratios of powder, paraffin, beeswax and oleic acid for hot press injection molding:

Powder: Paraffin: Beeswax: Oleic Acid

95%: 4%: 0.5%: 0.5%

The specific process is: weigh a certain amount of paraffin and beeswax, put them into a flask, heat them in a water bath at a constant temperature of 90°C until they are completely melted, then add a certain amount of oleic acid and stir with a glass rod, and add CaZr ₁ in several times after the oleic acid is evenly mixed. _-x In _x O _3-α (0.05≤x≤0.2) powder, after the powder is added, add the remaining oleic acid, paraffin and beeswax to improve the viscosity of the slurry, and then use mechanical stirring for 7 days to Degassing and homogenizing the slurry well.

Put the stirred slurry into the hot press injection molding machine, as shown in Figure 3, pour the stirred slurry 3 into the slurry cylinder 6 of the hot press injection molding machine, and control the wax slurry by heating the oil bath 7 The temperature is 90°C, and water 8 is filled between the slurry cylinder 6 and the heating oil bath 7 to facilitate heat transfer and uniform temperature, and the temperature of the grouting port is controlled by the heating wire 1 to be 50°C. After that, the mold 5 is placed at the mouth of the riser pipe 2 of the hot-press injection molding machine, and the mold 5 is pressed by the cylinder 4, and the pressure of the cylinder is controlled to be 0.3MPa, and the slurry 3 in the slurry cylinder is injected into the In the mold 5, the mold 5 was taken out after holding the pressure for 5 seconds, and demolded to obtain a solid electrolyte tube blank with one end open and one end closed. The outer diameter of the tube was 10 mm, the inner diameter was 7 mm, and the length was 30 mm.

Heat the formed pipe body under normal pressure and air atmosphere to remove wax. Wax removal temperature rise system: from room temperature to 150°C, the heating rate is 0.3°C/min; at 150°C, keep for 7 hours; from 150°C to 600°C, the heating rate is 0.5°C/min; at 600°C for 3 hours; The rate is 2°C/min; heat preservation at 1050°C for 3h; cool down to room temperature with the furnace.

The pipe body after dewaxing is put into a high-temperature sintering furnace, and sintered at high temperature under normal pressure and air atmosphere. The sintering heating system is as follows: from room temperature to 1100°C, the heating rate is 3°C/min; at 1100°C for 1 hour; from 1100°C to 1550°C, the heating rate is 2.5°C/min; at 1550°C for 5 hours; naturally cool to room temperature with the furnace. Finally, a CaZr _1-x In _x O _3-α (0.05≤x≤0.2) ceramic solid electrolyte tube is obtained.

The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the content disclosed in this embodiment and the accompanying drawings. Therefore, all equivalents or modifications that do not deviate from the spirit disclosed in the present invention fall within the protection scope of the present invention.

Claims (4)

1. A method for forming a solid electrolyte tube, specifically comprising the steps of: (a.1) Forming slurry preparation: Prepare the electrolyte powder material and the flowable substance that should be able to be removed by subsequent heating to form a slurry; Described flowable substance is paraffin, beeswax and oleic acid, and its mass proportion is: Powder: Paraffin: Beeswax: Oleic Acid 80-95%: 16-4%: 3.0-0.5%: 1.0-0.1% Heat part of the paraffin wax and part of the beeswax in a water bath at a constant temperature of 70-90°C until it melts completely, then add a part of oleic acid and stir, and after the oleic acid is mixed evenly, add CaZr _1-x In _x O _3-α powder several times, among which , 0.05≤x≤0.2, after the powder is added, add the remaining oleic acid, paraffin and beeswax to improve the viscosity of the slurry, then stir to remove the gas, and get a uniform slurry; (a.2) Hot press injection molding: Pour the slurry into the slurry cylinder of the hot press injection molding machine, control the temperature of the wax slurry to 70-90°C through the heating oil bath, and fill the heat transfer liquid medium between the slurry cylinder and the heating oil bath to facilitate heat transfer and uniform temperature , control the temperature of the grouting port at 40-50°C; then place the mold at the riser nozzle of the hot-press injection molding machine, use the cylinder to compress the mold, control the cylinder pressure to 0.3-0.5MPa, and press the slurry cylinder to Inject the slurry into the mold, hold the pressure for 5-15 seconds, take out the mold, demold the mold, and obtain the electrolyte tube; (a.3) Wax removal: Heat the formed electrolyte tube under normal pressure and air atmosphere to remove wax. The temperature rise system for wax removal is as follows: from room temperature to 100-150°C, with a heating rate of 0.1-0.3°C/min; at 100-150°C, keep warm for 3-7 hours; 100～150℃ to 400～600℃, the heating rate is 0.2～0.5℃/min; 400～600℃ for 1～3h; 400～600℃ to 950～1050℃, the heating rate is 0.5～2℃/min; 950 ～1050℃ for 1～3h; cool down to room temperature with the furnace; (a.4) Sintering: Sinter the electrolyte tube after dewaxing at high temperature under normal pressure and air atmosphere. ℃ to 1450-1550 ℃, the heating rate is 1.5-2.5 ℃/min; 1450-1550 ℃ heat preservation 5-15h; cool to room temperature with the furnace, and finally obtain a solid electrolyte tube. 2. A method for forming a solid electrolyte tube according to claim 1, characterized in that one end of the electrolyte tube obtained in step (a.2) is open and one end is closed, the outer diameter of the tube is 7-10 mm, and the inner diameter is 3-6 mm. The tube length is 15-30mm. 3. A forming method of the solid electrolyte tube according to claim 1 or 2, the preparation process of the solid electrolyte material comprises the steps of: (b.1) Compounding: The molar ratio of CaCO ₃ , ZrO ₂ and In ₂ O ₃ is: CaCO ₃ : ZrO ₂ : In ₂ O ₃ = 1: 0.8~0.95: 0.025~0.1 for wet ball milling at a speed of 200~300r/min Alternate forward and reverse ball milling for 8 to 24 hours, dry after ball milling, and then sieve the dried powder to obtain a mixed powder with a particle size of less than 5 μm; (b.2) Solid phase synthesis: Pour the sifted mixed powder into a mold to make a disc, put the pressed tablet into a high-temperature calcination furnace, perform high-temperature solid-phase reaction synthesis under normal pressure and air atmosphere, and then cool to room temperature with the furnace ; (b.3) Pulverization: The solid electrolyte sheet synthesized by the high-temperature solid-state reaction is crushed, then subjected to wet ball milling, and then dried and sieved to obtain an electrolyte powder with a particle size of less than 5 μm. 4. The forming method of the solid electrolyte tube according to claim 3, characterized in that, in step (b.2), the process parameters of the high-temperature solid-phase reaction are: First raise the temperature from room temperature to 700-900°C, with a heating rate of 5-10°C/min; then keep warm at 700-900°C for 0.5-2 hours; min, 1000-1400°C for 5-15 hours; cool to room temperature with the furnace; in step (1.3), the specific process of wet ball milling is: crush the flakes obtained by high-temperature solid-phase reaction, put them into a ball mill and add appropriate amount of Water ethanol or acetone wet ball milling, at a speed of 200-300r/min, forward and reverse intermittently alternate ball milling, the interval time of each ball milling is 10-30 minutes, and the cumulative ball milling hours are 8-24 hours.